1. Field of the Invention
The present invention relates to the field of detecting devices. More particularly, this invention relates to a digital multi range liquid level detector to verify and maintain a predetermined level of liquid in a container.
2. Prior Art
Liquid level detection is important in many applications. For instance, in a swimming pool, water level can vary significantly due to swimmer activities, water leak in accessories such as solar heater and evaporation. These problems can cause damage to the pump and sidewall of the pool. Several inventors have tried to solve these problems by adding mechanical floating valves or floats combined with electric solenoid but all these inventions involve a mechanical floating device.
For example, U.S. Pat. No. 10,415,526 shows a liquid level controller including a radio frequency transmitter and receiver. The transmitter determines the water level using a floating magnet which closes a magnetic switch in lower and upper position. The movable floating magnet is installed in a perforated hollow cylinder. The floating magnet can get stuck in the hollow cylinder and cause failures.
U.S. Pat. No. 10,823,184 shows a similar device except that they use an immersed probe. U.S. Pat. No. 10,394,947 shows a capacitive sensor that's use a reference electrode and a capacitive electrode of larger area. While such a system is workable, improvements are desirable.